The final piece to the puzzle is the animalís back-to-belly measurement. Once we know that, some very simple math will allow us to develop sight pictures at various target ranges. For illustration purposes, letís assume we are to hunt mule deer bucks with an expected backbone-to-belly measurement of eighteen inches. As stated previously, our goal is to place bullets in the vertical center of the buckís body. In this case, that equates to nine inches below the top of the buckís back. Using the data derived for my gun, at 125 yards we know the bead covers 10 inches and bullets hit 7 inches BTB. Therefore, if we were to place the top of the bead at the top of the mule deer buckís back, the bullet should hit 7 inches below the top of the back. Since we want the bullet to strike 9 inches below the top of the back, we must lower our aim so that the top of the bead is positioned 2 inches below the top of the back. The proper sight picture, drawn to scale, can be seen in Figure 2.
Letís perform the same series of manipulations to arrive at the proper sight picture for a mule deer located 150 yards away. From our previously gathered data, we note that the front bead covers 13 inches at this distance, and bullet drop is 9 inches BTB. In this particular case, bullet drop just happens to fall 9 inches BTB, which is perfect for an eighteen-inch animal. Therefore, the correct sight picture, as shown in Figure 3, would involve placing the top of the bead at the top of the buckís back.
Finally, letís see what sight picture works for a buck located 250 yards distant. At this range, the bead covers 23 inches and bullets hit 41 inches BTB. Stated differently, this means bullets will strike 18 inches below the bottom of the bead (23 + 18 = 41). If the bottom of the bead were held at the top of the back, bullets would hit 9 inches too low. Therefore, we need to elevate aim by 9 inches to hit the vertical center of the buck. The correct sight picture would have 9 inches of space between the bottom of the bead and the top of the buckís back (See Figure 4). Please notice that, in this instance, I described the correct hold in terms of the bottom of the bead instead of the top of the bead. The only reason for doing so is thatís itís much easier to estimate 9 inches of space between the animalís back and the bottom of the bead, than it is to estimate 32 inches (23 + 9 = 32) from the top of the bead to the top of the back.
In conclusion, this system uses two distinct and universally available reference points to facilitate aiming: the top of the rifleís front sight and the top of the animalís back. Combined with the known (or estimated) backbone-to-belly dimension of the animal being hunted, a series of range-appropriate sight pictures can be created, allowing precise bullet placement at ranges well beyond those achievable using more conventional aiming techniques. Before I developed this aiming technique, I wouldnít have contemplated shooting at anything beyond 125 yards. After making the aforementioned alterations in my iron sights and adopting the aiming convention I described, Iíve doubled the effective range of my muzzleloader, routinely placing 90% of my shots in the vital zone of my practice targets at 250 yards! Of course, this improvement didnít happen overnight, but it wouldnít have happened at all if I hadnít altered my equipment and my approach.
This article is a condensed version of a chapter in the authorís book: Great Shot! A Guide to Acquiring Shooting Skills for Big-Game Hunters, available at www.paulccarter.com.
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